Light Fixtures with LEDs are becoming increasingly popular due to following advantages over fluorescent tubes and/or incandescent bulbs and: (a) lower power consumption, (b) longer life expectancy, (c) vibration and shock resistance of LEDs. Although the power saving of LED light fixtures is apparent, however, if the lights remain on in an area where no lights is needed, enormous amount of energy has been wasted by streetlights, illumination of office buildings, hallways, flood-lights of parking lots, and farms, when sufficient ambient lighting exist. On the other hand, certain places such as hallways, office buildings and parking lots must maintain sufficient lighting to ensure the safety and security of the occupants. Therefore, the mandate of conserving energy and natural resources requires the owner of these places to provide sufficient lighting where the lighting is needed, but automatically adjust the lighting (energy consumption) while the ambient light changes and turn off the lighting when the places are sufficiently illuminated.
The traditional method is to turn off lights by means of mechanical switches, timers, or photo-diode sensors, however, these add further cost and wiring complexity, and as all electronic components are prone to failure which increases the return rate, services calls, and service requirements of the product. The key disadvantages of these approaches are: (a) the mechanical switches and timers can't maintain the lighting in place where the lighting is always needed, and (b) photo-diode sensors can turn off the lighting at certain ambient light level, but they are unable to maintain minimum consumption of energy. A system that can (a) provide lighting when it is dark, (b) provide supplemental lighting when ambient light is low, and (c) can turn off the lighting when the ambient light reaches a predetermined threshold, is desirable.
Therefore, heretofore unaddressed needs still exist in the art to address the aforementioned deficiencies and inadequacies.